.macro ACMultiplexed
  cbi     ADCSRA, ADEN          ; disable ADC
  in	  temp1, SFIOR
  sbr	  temp1, (1<<ACME)	; switch to comparator multiplexed
  out     SFIOR, temp1
.endmacro  

.macro ACNormal
   cbr	temp1, (1<<ACME)	; set to AN1
   out	SFIOR, temp1
   sbi	ADCSRA, ADEN		; enable ADC
.endmacro  

.macro ACChannel 
   ldi	 temp1, @0		
   out   ADMUX, temp1
.endmacro  
   